package com.jyy.prefabricated.utils;


import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.multipart.MultipartFile;
import org.apache.poi.xssf.usermodel.XSSFCell;
import javax.servlet.http.HttpServletResponse;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ExcelUtil {

    private static final Logger logger = LoggerFactory.getLogger(ExcelUtil.class);
    private final static String xls = "xls";
    private final static String xlsx = "xlsx";
    /**
     * 读入excel文件，解析后返回
     * @param file
     * @throws IOException
     */
    public static Map<String,Object> readExcel(MultipartFile file) throws IOException {
        //检查文件
        checkFile(file);
        //获得Workbook工作薄对象

        Workbook workbook = getWorkBook(file);
        Map<String,Object> result = new HashMap<>();
        //把单元格合并行当做二维数组来返回
        List<int[]> mergeDetail = new ArrayList<>();
        //创建返回对象，把每行中的值作为一个数组，所有行作为一个集合返回
        List<String[]> list = new ArrayList<String[]>();
        if(workbook != null){
            for(int sheetNum = 0;sheetNum < workbook.getNumberOfSheets();sheetNum++){
                //只解析第一个sheet页
                if(sheetNum == 0){
                    //获得当前sheet工作表
                    Sheet sheet = workbook.getSheetAt(sheetNum);
                    String sheetName = sheet.getSheetName();
                    if(sheet == null){
                        continue;
                    }

                    //获取合并单元格的行数
                    int sheetmergeCount = sheet.getNumMergedRegions();
                    if(sheetmergeCount > 0){
                        //获取单元格合并的行数和列数
                        for (int i = 0; i < sheetmergeCount; i++) {
                            int[] rowRange = new int[2];
                            CellRangeAddress range = sheet.getMergedRegion(i);
//                            int firstColumn = range.getFirstColumn();
//                            int lastColumn = range.getLastColumn();
                            int firstRow = range.getFirstRow();
                            int lastRow = range.getLastRow();
                            rowRange[0] = firstRow - 1;
                            rowRange[1] = lastRow - 1;
                            if(mergeDetail.size() > 0){
                                boolean flag = false;
                                for(int[] detail : mergeDetail){
                                    flag = !equalsArr(detail,rowRange);
                                }
                                if(flag){
                                    mergeDetail.add(rowRange);
                                }
                            }else {
                                mergeDetail.add(rowRange);
                            }
                        }
                    }

                    //获得当前sheet的开始行
                    int firstRowNum  = sheet.getFirstRowNum();
                    //获得当前sheet的结束行
                    int lastRowNum = sheet.getLastRowNum();
                    //循环除了第一行的所有行
                    for(int rowNum = firstRowNum+1;rowNum <= lastRowNum;rowNum++){
                        //获得当前行
                        Row row = sheet.getRow(rowNum);
                        if(row == null){
                            continue;
                        }
                        //获得当前行的开始列
                        int firstCellNum = row.getFirstCellNum();
                        //获得当前行的列数
                        int lastCellNum = row.getPhysicalNumberOfCells();
                        String[] cells = new String[row.getPhysicalNumberOfCells()];
                        //循环当前行
                        for(int cellNum = firstCellNum; cellNum < lastCellNum;cellNum++){
                            Cell cell = row.getCell(cellNum);
                            cells[cellNum] = getCellValue(cell);
                        }
                        if(cells.length == 9){
                            list.add(cells);
                        }
                    }
                }

            }
            workbook.close();
        }
        result.put("data",list);
        result.put("mergeDetail",mergeDetail);
        return result;
    }

    private static boolean equalsArr(int[] arr, int[] brr){
        if(arr.length == brr.length){
            for(int i=0; i<arr.length-1; i++){
                if(arr[i] == brr[i]){
                    return true;
                }else {
                    return false;
                }
            }
            return false;
        } else {
            return false;
        }
    }

    public static void checkFile(MultipartFile file) throws IOException{
        //判断文件是否存在
        if(null == file){
            logger.error("文件不存在！");
            throw new FileNotFoundException("文件不存在！");
        }
        //获得文件名
        String fileName = file.getOriginalFilename();
        //判断文件是否是excel文件
        if(!fileName.endsWith(xls) && !fileName.endsWith(xlsx)){
            logger.error(fileName + "不是excel文件");
            throw new IOException(fileName + "不是excel文件");
        }
    }
    public static Workbook getWorkBook(MultipartFile file) {
        //获得文件名
        String fileName = file.getOriginalFilename();
        //创建Workbook工作薄对象，表示整个excel
        Workbook workbook = null;
        try {
            //获取excel文件的io流
            InputStream is = file.getInputStream();
            //根据文件后缀名不同(xls和xlsx)获得不同的Workbook实现类对象
            if(fileName.endsWith(xls)){
                //2003
                workbook = new HSSFWorkbook(is);
            }else if(fileName.endsWith(xlsx)){
                //2007
                workbook = new XSSFWorkbook(is);
            }
        } catch (IOException e) {
            logger.info(e.getMessage());
        }
        return workbook;
    }


    private static String getCellValue(Cell cell){
        String cellValue = "";
        if(cell == null){
            return cellValue;
        }
        //把数字当成String来读，避免出现1读成1.0的情况
        if(cell.getCellType().equals(CellType.NUMERIC)){
            cell.setCellType(CellType.STRING);
        }
        //判断数据的类型
        switch (cell.getCellType()){
            case NUMERIC: //数字
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case STRING: //字符串
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case BOOLEAN: //Boolean
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case FORMULA: //公式
                cellValue = String.valueOf(cell.getCellFormula());
                break;
            case BLANK: //空值
                cellValue = "";
                break;
            case ERROR: //故障
                cellValue = "非法字符";
                break;
            default:
                cellValue = "未知类型";
                break;
        }
        return cellValue;
    }

    public static void downloadExcel(HttpServletResponse response, Workbook wb, String title)
        throws IOException {
        OutputStream output = response.getOutputStream();
        // 清空缓存
        response.reset();
        // 定义浏览器响应表头，顺带定义下载名
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Content-type", "text/html;charset=UTF-8");
        response.setHeader("Content-disposition",
            "attachment;filename=" + new String(title.getBytes(), "iso-8859-1") + ".xlsx");
        // 定义下载的类型，标明是excel文件
        response.setContentType("application/vnd.ms-excel");
        // 这时候把创建好的excel写入到输出流
        wb.write(output);
        // 关闭输出流
        output.close();
    }
}
